Public bug reported: == SRU Justification ==
[Impact] Oops during heavy NFS + FSCache + Cachefiles use: CacheFiles: Error: Overlong wait for old active object to go away. BUG: unable to handle kernel NULL pointer dereference at 0000000000000002 CacheFiles: Error: Object already active kernel BUG at fs/cachefiles/namei.c:163! [Cause] In a heavily loaded system with big files being read and truncated, an fscache object for a cookie is being dropped and a new object being looked. The new object being looked for has to wait for the old object to go away before the new object is moved to active state. [Fix] Clear the flag 'CACHEFILES_OBJECT_ACTIVE' for the new object when retrying the object lookup. Remove the BUG() for the case where the old object is still being dropped and convert to WARN() [Testcase] A user has run ~100 hours of NFS stress tests and not seen this bug recur. [Regression Potential] - Limited to fscache/cachefiles. ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1776254 Title: CacheFiles: Error: Overlong wait for old active object to go away. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1776254/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs